A PNP emitter follower probably works better than a resistor would in quickly discharging the gates of the MOSFETs. It might be non-desirable that R7 can bleed off the precious pv voltage. I have a MOFET relay built into my latest amp project. I got the MOSFET and the pv driver from avnet. I bench-tested the relay and it worked very well. The circuit is posted below if it helps. Q36 is the emitter follower:

Hi,
Just in case you want to try it attached it is schematic of my solid state relay using an avago Dual Channel Photovoltaic MOSFET Driver. I have been using it in my LM3886 amplifier for about one year with no problems. You can see the scope open/close time signal in my thread Protecting the speaker output using a microprocessor

Substituting a 2N5401/1N4148 per nattawa's diagram gave a longer turn-off time than the resistor in LTSpice. I got 65uS.

Using tauro0221's circuit, which looks a lot like one on Rod Elliott's site, required that I add another HCNR200 to the stack before it started to work. But once it did work in LTSpice, I got about a 5uS turn-off time. Not bad.

I'm not sure I understand these results. Maybe it has something to do with base/gate capacitance of the added PNP/NJFET.

The relatively new Vishay VOM1271 opto-photovoltaic device seems to be the best device to use for driving a pair of mosfet relay switches. It includes a fast turn off circuit. The opto LED needs to be driven between 10mA and 20mA for best results.

Paul, those switching times shown in the VOM1271 datasheet look good. But do I understand the waveform for the switching time test correctly? It appears that the output is inverted relative to the input. Is it an inverting device?

That Vishay driver looks very good. Using a standard photo coupler, you can get turn off times down to about 100 to 200 us (2 in parallel). The integrated turn off circuit is neat, and means you can create a really fast solid state loudspeaker relay.

I am Quite happy with the "old fashioned" PVI1050A .
Working great as a Songle 30A relay drop-in I made a while ago for my 5 channel HT amp with 5 LJM's L15D's .
very low RDsOn fast switch on an off , can't find scope pictures at the moment , but will keep looking .

Cheers ,

Rens

I know , some pins of the PV are not seated , but my rottie pinched my glasses from the bench before I took the picture of the PCB